Means for preventing axial vibrations of turbine and other shafts.



we.. A.

OSKAR ANTON WIB'ERG, OF FINSPONG, SWEDEN, ASEIGNOR. BY MFSNE ASSGNENES,

TO AKTIEBOLAGET LJUNGSTROMS ANGTURBXN, F STOCKHOL'M, SJVEDE. A @0R30- RATION.

IVIEANS FOR PBEVENTING AXIAL VIBBATIONS F TURBINE ANDIHER SHFTS.

Application filed May 24, 1918.

To all whom t lmay concern.'

Be it known that I, OSKAR ANTON 'Wienmn subject of the King of Sweden, residing in Finspong, Sweden, have invented certain new and useful Improvements in Means for Preventingr Axial Vibrations of' Turbine and other Shafts, otI which the following is a description.

It has already been proposed, for the purpose of preventing axial vibrations ot' turbine and similar rapidly rotating shafts to employ special arrangements in the :torni ot a liquid-brake or damper. The Construction of such arrangements as have heretofore been made has been somewhat eoxnplirated so that it has been a matter of great dillieulty to obtain a reliable action.

The present invention is intended lo l= about an arrangement of the kind mentioneL which will be at once simple and reliable in its action. The principal feature ot' the in,- vention resides in the fart that the damping or braking arrangement is eenstrurted in the form of'a liquidfbrake without valves.

In the accompanying drawing, Figure l shows an axial section of my improved ronstruetion taken on the section line indicated on Fig. 2; Fig. 2 a transverse section ot the same, and Figs. 25 and 4. are detail views showing modifications of the Connecting ports or passages of the braite-chambers.

ln the embodiment shown. in l and 2, 1 is a brakeeeylinder 'whit-h, in any'suitable way is firmly attached to a frame or support beyond the end of the turbine shaft and in such a position, that it lies eoaxially with 'the turbine-shaft. 2 is a piston` arranged in the said cylinder with an ineonsiderable periphe 'al Clearance. rlhe piston i2 is connected by a rod 3 with the end of the turbine or other shaft 4, the axial vibrations of which are to be damped. The rod 3 is oonneeted by a slip-joint, in this case a thrust. bearing, preterably a double acting ball bearing 5, with the piston 2, so that the latter need not take part in shaft. Thelength ol" the piston .)fis so proportioned with respect to that of the brake cylinder l that braio.: or tiuid Containing chambers 6 and 7 are formed on eat-h side thereof. These chambers eonnnunieate with each other by means or" the ineonsiderable clearance 8 between the piston :2 and the surrounding wall of the cylinder 1 so that liquid peelicaton o Letters Patent.

tions of the turbine or other shatt.

the rotation of the turbine or other.

'T2 r '1 wrm i- 's l atenten Non. nel, attire.

Serial No. 235.323.

can flow compara-tively slowly troni the one 5l brake chamberI to the other. The piston is provided with ('.ylindrieal hollow guidesen opposite sides, each ol wlieh makes s dine' tit with a eylinder head, the purpost of t arrangement bring; lo hold the piston Cent? with -respert to the axis ot the cylinder and preserve a uniform rlearanee around it.

vln order to obtain a. 'fully non--elastie damping` it is iinlriortant that no air or other gas shall collect in fhe brake \.'lnffl v` this purpose the inlet for the daan M (preferably oil) is arranged in a special which makes it diilieult 'l'or air or other to ind its way into the brui. cylinder addition to ti" the Cylinder is provided with an arrangement fo automatiealv 'per-- uiltlng the air or ,ons which may lind its way into the brake cylinder to e "cape, rlhe inlet pipe t) 'tor the liquid reeeivt ts supply from a suitable srmree under pressure and is connected with a rhanxber l0 arranged outside the ijn'aite cylinder proper and through whlrh the damping liquid must low downward in order to enter the port il leadinej inte the interior of 'the cylinder, the i'iort lil being arranged in the lewe part et the vyiinder. The )rt lll opens into an annular slot l2 in the wall of the brake eylimler; which .slot i; revered by the piston il so that the eonnertiini between the inlet and the 1 brake chambers through the Clearance whereby the damping; liquid is prevented from being; pressed bark to an;v emisiderzr degree through the inlet in eenseqinnee or the movements ot the piston due to vibrau@ lib-ove 'the inlet .f in the rhamber l@ is a small outlet 13 preferablyY governed by an adiustable needle valve .for the esrape el air or gas hat. enters with the oil; tin eti'eet of this ari ange Ine-nt is that, iinaetieally speaking, the oil enters the brake cylinder `free from air. i

Ations of minor adjustments Y large While that 'its position. the liquid in one liquid into the chamber 16 and is there pcrinitted to separate from the same and escape through the small outlet l?.

ccording to Fig. l the ports 14, l are in direct communication with the brake cliarnbers 6 and 7. But the ports can also be so arranged, as shown in Fig. 3, that their ds are covered by the piston 2 whereby they are in connection with the brake chambers 6 and 7 only through the restricted clearance 8. By this means there is obtained a throttling of the connection between the brake chambers so that on the vibrations of the turbine or otherI shaft only a-sniall part of the damping liquid can flow that Way. A similar eifect can also be obtained by arranging in the .connecting ports needle valves 18,19, as shown in Fig. a, by means of which valves the eiiiectivc cross sectional areas of the ports can be governed circumstances.

From the description it Will be seen that the main passage foi'tthe damping uid from one brake chamber to the other is ,through the restricted clearance 8 between the piston and the surrounding cylinder Wall, and that in shunt to this main path is another and relatively restricted passage comprising the passages lil. and and the chamber 16. Further that the ecctive area of this shunt passage may y both of the needle valves 18 and 19 and in this manner accurate adjustment of the apparatus obtained.

e apparatus depends the'itact according to for its action on that area of the piston is relatively of theelearance 8 and shunt passages. is comparatively small. rlfhis on the piston through the cannot respond l.freely i'or'in order to change must W through the restricted clearance .to vthe other, and due to this restriction an appreciable time interval-is required With the result of damping or restricting the vibra-- the turbine shaft. the outlets for air and gas are small means that only a sinall'amoiint of liquid can 'be :forced out of them when the piston moves and this is immediately made` up ,by the 'suppiy from. pipe 9.

will be seentliat the construction does aivay with all valves in the main fluid path andv that needle valves used only to 'make are provided. In this mannerall danger due to sluggish operation or complete failure is avoided. This results in zin-extremely simple piece of apparatus which is not liable to get out of order ben cause. there are no nicely'tted parts to be maintained. l

latent statutes, I have described the principle of operation of my invention, together upper end to permit be varied by adjusting one or thrust is exerted rod 3 the piston' brake chamber l outlet to the with the apparatus which l now consider to represent the best embodimentthereof, but

desire to have it understood that the apparatus shown is only illustrative, and that the invention can be carried out by other means.

-iiVhat l claim as new and desire to secure by Letters Patent of the United States, is,

ln an apparatus of the character described, rthe combination of a cylinder containing a damping fluid, a piston therein which d`vides the cylinder space into chambers which are connected' by a restricted clearance located between the piston and the surrounding cylinder wall and through which Huid is free to flou' at all times from one chamber to the other as the piston moves axially, means connecting the piston land the shaft Whose axial movements are to be damped, and va iiuid supply chamber arranged outside of the cylinder proper which cylinder space and has a free opening at its the escape of 2. In an apparatus of the scribed, thecombination of a cylinder containing a damping fluid, a piston therein Which divides the cylinder space into bers which are connected byla restricted clearance located between surrounding cylinder Wall `and through Which'uid is free to'liow at all times from one chamber to the other as the piston moves axially, means cdiihectingthe piston and the shaft Whose axial'. movements into said restricted Y tween the ends of the piston andmeans for supplyiiigjluid to lsaid port. 4' an apparatus of the character described,. the combination of cylinder containing a damling uidtxapiston therein whichv divides t eeyliiider e'into chambers which are con acted surrounding cylinder" wall and through Whichiiuid is free to' i'iowY at all times from one chamber to the other as the'p'iston moves axially, ineens connecting the piston and the y. 1;oy a' restricted clearance located lieti/'een the piston and the sha1-t Whose axial movements are to be amped, a chamber arranged outside the proper which is provided with an atmosphere, and passages leading from the chambers on opposite sides of the piston to said Chamb which iuid iiorvs. y

d. in an apparatus of the character described, 'tlie combination of a cylinder member closed at er and through l weasel to flow at all times @tween the chambers as the piston and cylinder more relatively to each other, a second passage connectingl said two chambers together, said passage forming a path for the liuid in shunt to the tiretv7 means for connecting one of the members with'the shaft Whose axial vibrations are to be restricted which includes a slip-joint so that the rotary movements oit' the shaft are not transmitted to the member connected thereto, and nieans connected te the cylinder for supplying fluid to said chambers.

Fi. ln an apparatus of the character des-z'l ibed, the combination et' a cylinder con; taining a damping duid, a piston therein dividing the cylinder space into chambers which are connected by a restricted clearance located between the piston and the surrounding cylinder Wall and through Which iuid is free to tion* at all. tiincs` troni one chamber to the other the piston moves axially, means connecting the piston and shaftwhose axial movements are 'to be damped Which includes a slipejoint s0 that the shaft can rotate independently ot the piston, a shunt passage for the fluid which comprises a chamber and restricted pas sages, the latter opening into the restricted clearance between the piston and surrounding cylinder wall.

6. In an apparatus oi the character described, the combination of a cylinder, a piston located therein which divides the cylinder space into two duid containing damping chambers withY a restricted connection between7 a means connectedto the piston and the shaft which is to be damped which perinits relative rotation of the arts, a supply chamber which is connected ily a port with the bottoni et the cylinder and has an opening yto atmosphere above said port to perinit air to escape, and a chamber situated above the cylinder to which seid Vdamping chambers are connected, said chambers haw ing an outlet for the escape et gas.

Y. ln a device of the character described, the combination of a stationary cylinder which. is provided with a. circumferential groove located between the ends of the piston stroke. a piston located in the cylinder which divides it into two Huid containing chambers, said piston being separated from the cylinder Wall by a restricted clearance through which fluid is free to ilove in limited quantities upon axial movement of the piston, a supply chamber having a discharge port opening into the groove, a vent for the chamber and ineens for supplying fluid to thechaniber. y

in testimony whereof l ria my signature in. presence of two Witnesses.

SAR ANTN WEBER@ Witnesses:

N. Anoniem?. EINAR bicentenaire?. 

